Effects of Blue Light Deficiency on Acclimation of Light Energy Partitioning in PSII and CO2 Assimilation Capacity to High Irradiance in Spinach Leaves

Abstract

Blue light effects on the acclimation of energy partitioning characteristics in PSII and CO2 assimilation capacity in spinach to high growth irradiance were investigated. Plants were grown hydroponically in different light treatments that were a combination of two light qualities and two irradiances,i.e. white light and blue-deficient light at photosynthetic photon flux densities (PPFDs) of 100 and 500 micromol m(-2) s(-1). The CO2 assimilation rate, the quantum efficiency of PSII(PhiPSII) and thermal dissipation activity (F(v)/F(m)-F'(v)/F'(m)) in young, fully expanded leaves were measured under 1,600 micromol m(-2) s(-1) white light. The CO2 assimilation rate and (PhiPSII) were higher, while F(v)/F(m)-F'(v)/F'(m) was lower in plants grown under high irradiance than in plants grown under low irradiance. These responses were observed irrespective of the presence or absence of blue light during growth. The extent of the increase in the CO2 assimilation rate and PhiPSII and the decrease in F(v)/F(m)-F'(v)/F'(m) by high growth irradiance was smaller under blue light-deficient conditions. These results indicate that blue light helps to boost the acclimation responses of energy partitioning in PSII and CO2 assimilation to high irradiance. Similarly, leaf N, Cyt f and Chl contents per unit leaf area increased by high growth irradiance, and the extent of the increment in leaf N, Cyt f and Chl was smaller under blue light-deficient conditions. Regression analysis showed that the differences in energy partitioning in PSIIand CO2 assimilation between plants grown under high white light and high blue-deficient light were closely related to the difference in leaf N.

Influence of IAA, TDZ, and light quality on asymbiotic germination, protocorm formation, and plantlet development of Cyrtopodium glutiniferum Raddi., a medicinal orchid

“…For Cattleya orchids, production of multiple green protocorms was also highest in green light (Islam et al 1999). According to Matsuda et al (2008), a larger blue-light fraction, as provided by the BL lamps used in our experiments, is generally associated with the development of ''sun-type'' plants. Besides, Rajapske and Kelly (1993) showed that plants grown under green and blue lights had similar responses, probably because cryptochromes are green-light receptors (Folta and Maruhnich 2007).…”

Morphological and Physiological Responses of <i>Morus alba</i> Seedlings under Different Light Qualities

“…Plants grown under blue light showed similar photosynthesis to those adapted to high light conditions (Matsuda et al, 2008). A relatively higher proportion of blue light can cause leaves to present so-called "sun type" characteristics and these leaves had high LMA and photosynthetic capacity (Matsuda et al, 2004;Matsuda et al, 2008;Hogewoning et al, 2010b). In this study, we found that the Pn of leaves grown under RB was higher than that of leaves grown under R and B, but had no significant difference compared with leaves grown under W (Fig.…”

“…Several studies showed that the Pn of plants grown under red light was lower than that of plants grown under white fluorescent light or a mixture of red and blue light (Goins et al, 1997;Yorio et al, 2001;Matsuda et al, 2004). Plants grown under blue light showed similar photosynthesis to those adapted to high light conditions (Matsuda et al, 2008). A relatively higher proportion of blue light can cause leaves to present so-called "sun type" characteristics and these leaves had high LMA and photosynthetic capacity (Matsuda et al, 2004;Matsuda et al, 2008;Hogewoning et al, 2010b).…”

Plant Responses to Extended Photosynthetically Active Radiation (EPAR)

“…In some investigations into plants, it has been tried to avoid the spectra out of PAR region by using a proper light source radiating within PAR, 36,37 or using filters to prevent plants from UV, FR, or IR spectra. [38][39][40] In most reports neither of these two techniques have been employed nor have been mentioned if used, this is in spite of the fact that data taken under artificial light sources are potentially the most erroneous ones. …”